/* write.c - emit .o file Copyright (C) 1986, 1987, 1990, 1991, 1992, 1993 Free Software Foundation, Inc. This file is part of GAS, the GNU Assembler. GAS is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GAS is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GAS; see the file COPYING. If not, write to the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */ /* This thing should be set up to do byteordering correctly. But... */ #include "as.h" #include "subsegs.h" #include "obstack.h" #include "output-file.h" /* The NOP_OPCODE is for the alignment fill value. Fill it with a nop instruction so that the disassembler does not choke on it. */ #ifndef NOP_OPCODE #define NOP_OPCODE 0x00 #endif #ifndef WORKING_DOT_WORD extern CONST int md_short_jump_size; extern CONST int md_long_jump_size; #endif #ifndef BFD_ASSEMBLER #ifndef MANY_SEGMENTS struct frag *text_frag_root; struct frag *data_frag_root; struct frag *bss_frag_root; struct frag *text_last_frag; /* Last frag in segment. */ struct frag *data_last_frag; /* Last frag in segment. */ static struct frag *bss_last_frag; /* Last frag in segment. */ #endif static object_headers headers; long string_byte_count; static char *the_object_file; char *next_object_file_charP; /* Tracks object file bytes. */ #ifndef OBJ_VMS int magic_number_for_object_file = DEFAULT_MAGIC_NUMBER_FOR_OBJECT_FILE; #endif #endif /* BFD_ASSEMBLER */ static long fixup_segment PARAMS ((fixS * fixP, segT this_segment_type)); static relax_addressT relax_align PARAMS ((relax_addressT addr, long align)); void relax_segment PARAMS ((struct frag * seg_frag_root, segT seg_type)); /* * fix_new() * * Create a fixS in obstack 'notes'. */ fixS * fix_new (frag, where, size, add_symbol, sub_symbol, offset, pcrel, r_type) fragS *frag; /* Which frag? */ int where; /* Where in that frag? */ short int size; /* 1, 2, or 4 usually. */ symbolS *add_symbol; /* X_add_symbol. */ symbolS *sub_symbol; /* X_subtract_symbol. */ long offset; /* X_add_number. */ int pcrel; /* TRUE if PC-relative relocation. */ #ifdef BFD_ASSEMBLER bfd_reloc_code_real_type r_type; /* Relocation type */ #else int r_type; /* Relocation type */ #endif { fixS *fixP; fixP = (fixS *) obstack_alloc (¬es, sizeof (fixS)); fixP->fx_frag = frag; fixP->fx_where = where; fixP->fx_size = size; fixP->fx_addsy = add_symbol; fixP->fx_subsy = sub_symbol; fixP->fx_offset = offset; fixP->fx_pcrel = pcrel; #if defined(NEED_FX_R_TYPE) || defined (BFD_ASSEMBLER) fixP->fx_r_type = r_type; #endif fixP->fx_im_disp = 0; fixP->fx_pcrel_adjust = 0; fixP->fx_bit_fixP = 0; fixP->fx_addnumber = 0; #ifdef TC_something fixP->fx_bsr = 0; #endif #ifdef TC_I960 fixP->fx_callj = 0; #endif /* Usually, we want relocs sorted numerically, but while comparing to older versions of gas that have relocs reverse sorted, it is convenient to have this compile time option. xoxorich. */ { #ifdef BFD_ASSEMBLER fixS **seg_fix_rootP = & (seg_info (now_seg)->fix_root); fixS **seg_fix_tailP = & (seg_info (now_seg)->fix_tail); #endif #ifdef REVERSE_SORT_RELOCS fixP->fx_next = *seg_fix_rootP; *seg_fix_rootP = fixP; #else /* REVERSE_SORT_RELOCS */ fixP->fx_next = NULL; if (*seg_fix_tailP) (*seg_fix_tailP)->fx_next = fixP; else *seg_fix_rootP = fixP; *seg_fix_tailP = fixP; #endif /* REVERSE_SORT_RELOCS */ } return fixP; } /* Append a string onto another string, bumping the pointer along. */ void append (charPP, fromP, length) char **charPP; char *fromP; unsigned long length; { /* Don't trust memcpy() of 0 chars. */ if (length == 0) return; memcpy (*charPP, fromP, (int) length); *charPP += length; } #ifndef BFD_ASSEMBLER int section_alignment[SEG_MAXIMUM_ORDINAL]; #endif /* * This routine records the largest alignment seen for each segment. * If the beginning of the segment is aligned on the worst-case * boundary, all of the other alignments within it will work. At * least one object format really uses this info. */ void record_alignment (seg, align) /* Segment to which alignment pertains */ segT seg; /* Alignment, as a power of 2 (e.g., 1 => 2-byte boundary, 2 => 4-byte boundary, etc.) */ int align; { #ifdef BFD_ASSEMBLER if (align > bfd_get_section_alignment (stdoutput, seg)) bfd_set_section_alignment (stdoutput, seg, align); #else if (align > section_alignment[(int) seg]) section_alignment[(int) seg] = align; #endif } #if defined (BFD_ASSEMBLER) || ! defined (BFD) static fragS * chain_frchains_together_1 (section, frchp) segT section; struct frchain *frchp; { fragS dummy, *prev_frag = &dummy; for (; frchp && frchp->frch_seg == section; frchp = frchp->frch_next) { prev_frag->fr_next = frchp->frch_root; prev_frag = frchp->frch_last; } prev_frag->fr_next = 0; return prev_frag; } #endif #ifdef BFD_ASSEMBLER static void chain_frchains_together (abfd, section, xxx) bfd *abfd; /* unused */ segT section; char *xxx; /* unused */ { segment_info_type *info; /* BFD may have introduced its own sections without using subseg_new, so it is possible that seg_info is NULL. */ info = seg_info (section); if (info != (segment_info_type *) NULL) chain_frchains_together_1 (section, info->frchainP); } #endif #ifndef BFD void remove_subsegs (head, seg, root, last) frchainS *head; int seg; fragS **root; fragS **last; { *root = head->frch_root; *last = chain_frchains_together_1 (seg, head); } #endif /* BFD */ #ifndef BFD static void cvt_frag_to_fill (x, fragP) #ifdef BFD_ASSEMBLER segT x; #else object_headers *x; #endif fragS *fragP; { #ifdef BFD_ASSEMBLER segT sec = x; #else object_headers *headers = x; #endif switch (fragP->fr_type) { case rs_align: case rs_org: #ifdef HANDLE_ALIGN HANDLE_ALIGN (fragP); #endif fragP->fr_type = rs_fill; know (fragP->fr_var == 1); know (fragP->fr_next != NULL); fragP->fr_offset = (fragP->fr_next->fr_address - fragP->fr_address - fragP->fr_fix); break; case rs_fill: break; case rs_machine_dependent: #ifdef BFD_ASSEMBLER md_convert_frag (stdoutput, sec, fragP); #else md_convert_frag (headers, fragP); #endif assert (fragP->fr_next == NULL \ || (fragP->fr_next->fr_address - fragP->fr_address \ == fragP->fr_fix)); /* * After md_convert_frag, we make the frag into a ".space 0". * Md_convert_frag() should set up any fixSs and constants * required. */ frag_wane (fragP); break; #ifndef WORKING_DOT_WORD case rs_broken_word: { struct broken_word *lie; if (fragP->fr_subtype) { fragP->fr_fix += md_short_jump_size; for (lie = (struct broken_word *) (fragP->fr_symbol); lie && lie->dispfrag == fragP; lie = lie->next_broken_word) if (lie->added == 1) fragP->fr_fix += md_long_jump_size; } frag_wane (fragP); } break; #endif default: BAD_CASE (fragP->fr_type); break; } } #ifdef BFD_ASSEMBLER static void relax_and_size_seg (abfd, sec, xxx) bfd *abfd; asection *sec; char *xxx; { flagword flags; flags = bfd_get_section_flags (abfd, sec); if (flags & SEC_ALLOC) { fragS *fragp; segment_info_type *seginfo; int x; unsigned long size, newsize; seginfo = (segment_info_type *) bfd_get_section_userdata (abfd, sec); relax_segment (seginfo->frchainP->frch_root, sec); for (fragp = seginfo->frchainP->frch_root; fragp; fragp = fragp->fr_next) cvt_frag_to_fill (sec, fragp); for (fragp = seginfo->frchainP->frch_root; fragp->fr_next; fragp = fragp->fr_next) /* walk to last elt */; size = fragp->fr_address; if (size > 0) { flags |= SEC_HAS_CONTENTS; /* @@ This is just an approximation. */ if (seginfo->fix_root) flags |= SEC_RELOC; x = bfd_set_section_flags (abfd, sec, flags); assert (x == true); } size = md_section_align (sec, size); x = bfd_set_section_size (abfd, sec, size); assert (x == true); /* If the size had to be rounded up, add some padding in the last non-empty frag. */ newsize = bfd_get_section_size_before_reloc (sec); assert (newsize >= size); if (size != newsize) { fragS *last = seginfo->frchainP->frch_last; fragp = seginfo->frchainP->frch_root; while (fragp->fr_next != last) fragp = fragp->fr_next; last->fr_address = size; fragp->fr_offset += newsize - size; } } #ifdef tc_frob_section tc_frob_section (sec); #endif #ifdef obj_frob_section obj_frob_section (sec); #endif } static void write_contents (abfd, sec, xxx) bfd *abfd; asection *sec; char *xxx; { segment_info_type *seginfo = seg_info (sec); unsigned long offset = 0; fragS *frags; int i, n; arelent **relocs; fixS *fixp; if (! (bfd_get_section_flags (abfd, sec) & SEC_LOAD)) return; fixup_segment (seginfo->fix_root, sec); for (i = 0, fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next) if (fixp->fx_addsy) { symbolS *sym = fixp->fx_addsy; asection *sec = sym->bsym->section; if (sec == &bfd_und_section || sec == &bfd_abs_section || sec == &bfd_com_section) continue; if (sym->bsym == sec->symbol) continue; /* If the section symbol isn't going to be output, the relocs at least should still work. If not, figure out what to do when we run into that case. */ fixp->fx_offset += S_GET_VALUE (sym); fixp->fx_addsy = symbol_find (sec->name); if (!fixp->fx_addsy) { fixp->fx_addsy = symbol_make (sec->name); fixp->fx_addsy->bsym = sec->symbol; } } /* Force calculations (size, vma) to get done. */ bfd_set_section_contents (stdoutput, sec, "", 0, 0); /* Set up reloc information as well. */ n = 0; for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next) n++; relocs = (arelent **) bfd_alloc_by_size_t (stdoutput, n * sizeof (arelent *)); for (frags = seginfo->frchainP->frch_root, fixp = seginfo->fix_root, i = 0; frags; frags = frags->fr_next) { int x; unsigned long fill_size; char *fill_literal; long count; assert (frags->fr_type == rs_fill); while (fixp && fixp->fx_frag == frags) { arelent *reloc; extern arelent *tc_gen_reloc (); char *data; static bfd_reloc_status_type s; if (fixp->fx_addsy == 0) { /* @@ Need some other flag to indicate which have already been performed... */ n--; goto next; } reloc = tc_gen_reloc (sec, fixp); if (!reloc) { n--; goto next; } data = frags->fr_literal + fixp->fx_where; if (fixp->fx_where + 4 > frags->fr_fix + frags->fr_offset) abort (); s = bfd_perform_relocation (stdoutput, reloc, data - reloc->address, sec, stdoutput); switch (s) { case bfd_reloc_ok: break; default: printf ("bad s value\n"); abort (); } relocs[i++] = reloc; next: fixp = fixp->fx_next; } if (frags->fr_fix) { x = bfd_set_section_contents (stdoutput, sec, frags->fr_literal, offset, frags->fr_fix); assert (x == true); offset += frags->fr_fix; } fill_literal = frags->fr_literal + frags->fr_fix; fill_size = frags->fr_var; count = frags->fr_offset; assert (count >= 0); if (fill_size && count) while (count--) { x = bfd_set_section_contents (stdoutput, sec, fill_literal, offset, fill_size); assert (x == true); offset += fill_size; } } /* Did we miss any relocs? */ if (fixp != 0) abort (); if (n) bfd_set_reloc (stdoutput, sec, relocs, n); } #endif void write_object_file () { register struct frchain *frchainP; /* Track along all frchains. */ register fragS *fragP; /* Track along all frags. */ register struct frchain *next_frchainP; register fragS **prev_fragPP; long object_file_size; /* Do we really want to write it? */ { int n_warns, n_errs; n_warns = had_warnings (); n_errs = had_errors (); /* The -Z flag indicates that an object file should be generated, regardless of warnings and errors. */ if (flagseen['Z']) { if (n_warns || n_errs) as_warn ("%d error%s, %d warning%s, generating bad object file.\n", n_errs, n_errs == 1 ? "" : "s", n_warns, n_warns == 1 ? "" : "s"); } else { if (n_errs) as_fatal ("%d error%s, %d warning%s, no object file generated.\n", n_errs, n_errs == 1 ? "" : "s", n_warns, n_warns == 1 ? "" : "s"); } } #ifdef OBJ_VMS /* * Under VMS we try to be compatible with VAX-11 "C". Thus, we * call a routine to check for the definition of the procedure * "_main", and if so -- fix it up so that it can be program * entry point. */ VMS_Check_For_Main (); #endif /* VMS */ /* After every sub-segment, we fake an ".align ...". This conforms to BSD4.2 brane-damage. We then fake ".fill 0" because that is the kind of frag that requires least thought. ".align" frags like to have a following frag since that makes calculating their intended length trivial. @@ Is this really necessary?? */ #ifndef SUB_SEGMENT_ALIGN #ifdef BFD_ASSEMBLER #define SUB_SEGMENT_ALIGN(SEG) (0) #else #define SUB_SEGMENT_ALIGN(SEG) (2) #endif #endif for (frchainP = frchain_root; frchainP; frchainP = frchainP->frch_next) { #ifdef BFD_ASSEMBLER subseg_set (frchainP->frch_seg, frchainP->frch_subseg); #else subseg_new (frchainP->frch_seg, frchainP->frch_subseg); #endif frag_align (SUB_SEGMENT_ALIGN (now_seg), NOP_OPCODE); /* frag_align will have left a new frag. Use this last frag for an empty ".fill". For this segment ... Create a last frag. Do not leave a "being filled in frag". */ frag_wane (frag_now); frag_now->fr_fix = 0; know (frag_now->fr_next == NULL); /* know( frags . obstack_c_base == frags . obstack_c_next_free ); */ /* Above shows we haven't left a half-completed object on obstack. */ } /* From now on, we don't care about sub-segments. Build one frag chain for each segment. Linked thru fr_next. */ #ifdef BFD_ASSEMBLER /* Remove the sections created by gas for its own purposes. */ { asection **seclist, *sec; seclist = &stdoutput->sections; while (seclist && *seclist) { sec = *seclist; while (sec == big_section || sec == reg_section || sec == pass1_section || sec == diff_section || sec == absent_section) { sec = sec->next; *seclist = sec; stdoutput->section_count--; if (!sec) break; } if (*seclist) seclist = &(*seclist)->next; } } bfd_map_over_sections (stdoutput, chain_frchains_together, (char *) 0); #else remove_subsegs (frchain_root, SEG_TEXT, &text_frag_root, &text_last_frag); remove_subsegs (data0_frchainP, SEG_DATA, &data_frag_root, &data_last_frag); remove_subsegs (bss0_frchainP, SEG_BSS, &bss_frag_root, &bss_last_frag); #endif /* We have two segments. If user gave -R flag, then we must put the data frags into the text segment. Do this before relaxing so we know to take advantage of -R and make shorter addresses. */ #if !defined (OBJ_AOUT) || defined (BFD_ASSEMBLER) if (flagseen['R']) { #ifdef BFD_ASSEMBLER seg_info (text_section)->frchainP->frch_last->fr_next = seg_info (data_section)->frchainP->frch_root; seg_info (text_section)->frchainP->frch_last = seg_info (data_section)->frchainP->frch_last; seg_info (data_section)->frchainP = 0; #else fixS *tmp; text_last_frag->fr_next = data_frag_root; text_last_frag = data_last_frag; data_last_frag = NULL; data_frag_root = NULL; if (text_fix_root) { for (tmp = text_fix_root; tmp->fx_next; tmp = tmp->fx_next);; tmp->fx_next = data_fix_root; text_fix_tail = data_fix_tail; } else text_fix_root = data_fix_root; data_fix_root = NULL; #endif } #endif #ifdef BFD_ASSEMBLER bfd_map_over_sections (stdoutput, relax_and_size_seg, (char *) 0); #else relax_segment (text_frag_root, SEG_TEXT); relax_segment (data_frag_root, SEG_DATA); relax_segment (bss_frag_root, SEG_BSS); /* * Now the addresses of frags are correct within the segment. */ know (text_last_frag->fr_type == rs_fill && text_last_frag->fr_offset == 0); H_SET_TEXT_SIZE (&headers, text_last_frag->fr_address); text_last_frag->fr_address = H_GET_TEXT_SIZE (&headers); /* * Join the 2 segments into 1 huge segment. * To do this, re-compute every rn_address in the SEG_DATA frags. * Then join the data frags after the text frags. * * Determine a_data [length of data segment]. */ if (data_frag_root) { register relax_addressT slide; know ((text_last_frag->fr_type == rs_fill) && (text_last_frag->fr_offset == 0)); H_SET_DATA_SIZE (&headers, data_last_frag->fr_address); data_last_frag->fr_address = H_GET_DATA_SIZE (&headers); slide = H_GET_TEXT_SIZE (&headers); /* & in file of the data segment. */ #ifdef OBJ_BOUT #define RoundUp(N,S) (((N)+(S)-1)&-(S)) /* For b.out: If the data section has a strict alignment requirement, its load address in the .o file will be rounded up from the size of the text section. These two values are *not* the same! Similarly for the bss section.... */ slide = RoundUp (slide, 1 << section_alignment[SEG_DATA]); #endif for (fragP = data_frag_root; fragP; fragP = fragP->fr_next) { fragP->fr_address += slide; } /* for each data frag */ know (text_last_frag != 0); text_last_frag->fr_next = data_frag_root; } else { H_SET_DATA_SIZE (&headers, 0); } #ifdef OBJ_BOUT /* See above comments on b.out data section address. */ { long bss_vma; if (data_last_frag == 0) bss_vma = H_GET_TEXT_SIZE (&headers); else bss_vma = data_last_frag->fr_address; bss_vma = RoundUp (bss_vma, 1 << section_alignment[SEG_BSS]); bss_address_frag.fr_address = bss_vma; } #else /* ! OBJ_BOUT */ bss_address_frag.fr_address = (H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers)); /* Slide all the frags */ if (bss_frag_root) { relax_addressT slide = bss_address_frag.fr_address; for (fragP = bss_frag_root; fragP; fragP = fragP->fr_next) { fragP->fr_address += slide; } /* for each bss frag */ } #endif /* ! OBJ_BOUT */ if (bss_last_frag) H_SET_BSS_SIZE (&headers, bss_last_frag->fr_address - bss_frag_root->fr_address); else H_SET_BSS_SIZE (&headers, 0); #endif /* BFD_ASSEMBLER */ #ifndef BFD_ASSEMBLER /* * * Crawl the symbol chain. * * For each symbol whose value depends on a frag, take the address of * that frag and subsume it into the value of the symbol. * After this, there is just one way to lookup a symbol value. * Values are left in their final state for object file emission. * We adjust the values of 'L' local symbols, even if we do * not intend to emit them to the object file, because their values * are needed for fix-ups. * * Unless we saw a -L flag, remove all symbols that begin with 'L' * from the symbol chain. (They are still pointed to by the fixes.) * * Count the remaining symbols. * Assign a symbol number to each symbol. * Count the number of string-table chars we will emit. * Put this info into the headers as appropriate. * */ know (zero_address_frag.fr_address == 0); string_byte_count = sizeof (string_byte_count); obj_crawl_symbol_chain (&headers); if (string_byte_count == sizeof (string_byte_count)) string_byte_count = 0; H_SET_STRING_SIZE (&headers, string_byte_count); /* * Addresses of frags now reflect addresses we use in the object file. * Symbol values are correct. * Scan the frags, converting any ".org"s and ".align"s to ".fill"s. * Also converting any machine-dependent frags using md_convert_frag(); */ subseg_change (SEG_TEXT, 0); for (fragP = text_frag_root; fragP; fragP = fragP->fr_next) { cvt_frag_to_fill (&headers, fragP); /* Some assert macros don't work with # directives mixed in. */ #ifndef NDEBUG if (!(fragP->fr_next == NULL #ifdef OBJ_BOUT || fragP->fr_next == data_frag_root #endif || ((fragP->fr_next->fr_address - fragP->fr_address) == (fragP->fr_fix + fragP->fr_offset * fragP->fr_var)))) abort (); #endif } #endif /* ! BFD_ASSEMBLER */ #ifndef WORKING_DOT_WORD { struct broken_word *lie; struct broken_word **prevP; prevP = &broken_words; for (lie = broken_words; lie; lie = lie->next_broken_word) if (!lie->added) { #ifdef BFD_ASSEMBLER fix_new (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, lie->add, lie->sub, lie->addnum, 0, BFD_RELOC_NONE); #else #if defined(TC_SPARC) || defined(TC_A29K) || defined(NEED_FX_R_TYPE) fix_new (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, lie->add, lie->sub, lie->addnum, 0, NO_RELOC); #else #ifdef TC_NS32K fix_new_ns32k (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, lie->add, lie->sub, lie->addnum, 0, 0, 2, 0, 0); #else fix_new (lie->frag, lie->word_goes_here - lie->frag->fr_literal, 2, lie->add, lie->sub, lie->addnum, 0, 0); #endif /* TC_NS32K */ #endif /* TC_SPARC|TC_A29K|NEED_FX_R_TYPE */ #endif /* BFD_ASSEMBLER */ *prevP = lie->next_broken_word; } else prevP = &(lie->next_broken_word); for (lie = broken_words; lie;) { struct broken_word *untruth; char *table_ptr; long table_addr; long from_addr, to_addr; int n, m; fragP = lie->dispfrag; /* Find out how many broken_words go here. */ n = 0; for (untruth = lie; untruth && untruth->dispfrag == fragP; untruth = untruth->next_broken_word) if (untruth->added == 1) n++; table_ptr = lie->dispfrag->fr_opcode; table_addr = lie->dispfrag->fr_address + (table_ptr - lie->dispfrag->fr_literal); /* Create the jump around the long jumps. This is a short jump from table_ptr+0 to table_ptr+n*long_jump_size. */ from_addr = table_addr; to_addr = table_addr + md_short_jump_size + n * md_long_jump_size; md_create_short_jump (table_ptr, from_addr, to_addr, lie->dispfrag, lie->add); table_ptr += md_short_jump_size; table_addr += md_short_jump_size; for (m = 0; lie && lie->dispfrag == fragP; m++, lie = lie->next_broken_word) { if (lie->added == 2) continue; /* Patch the jump table */ /* This is the offset from ??? to table_ptr+0 */ to_addr = table_addr - S_GET_VALUE (lie->sub); md_number_to_chars (lie->word_goes_here, to_addr, 2); for (untruth = lie->next_broken_word; untruth && untruth->dispfrag == fragP; untruth = untruth->next_broken_word) { if (untruth->use_jump == lie) md_number_to_chars (untruth->word_goes_here, to_addr, 2); } /* Install the long jump */ /* this is a long jump from table_ptr+0 to the final target */ from_addr = table_addr; to_addr = S_GET_VALUE (lie->add) + lie->addnum; md_create_long_jump (table_ptr, from_addr, to_addr, lie->dispfrag, lie->add); table_ptr += md_long_jump_size; table_addr += md_long_jump_size; } } } #endif /* not WORKING_DOT_WORD */ #ifndef BFD_ASSEMBLER #ifndef OBJ_VMS { /* not vms */ /* * Scan every FixS performing fixups. We had to wait until now to do * this because md_convert_frag() may have made some fixSs. */ int trsize, drsize; subseg_change (SEG_TEXT, 0); trsize = md_reloc_size * fixup_segment (text_fix_root, SEG_TEXT); subseg_change (SEG_DATA, 0); drsize = md_reloc_size * fixup_segment (data_fix_root, SEG_DATA); H_SET_RELOCATION_SIZE (&headers, trsize, drsize); /* FIXME move this stuff into the pre-write-hook */ H_SET_MAGIC_NUMBER (&headers, magic_number_for_object_file); H_SET_ENTRY_POINT (&headers, 0); obj_pre_write_hook (&headers); /* extra coff stuff */ object_file_size = H_GET_FILE_SIZE (&headers); next_object_file_charP = the_object_file = xmalloc (object_file_size); output_file_create (out_file_name); obj_header_append (&next_object_file_charP, &headers); know ((next_object_file_charP - the_object_file) == H_GET_HEADER_SIZE (&headers)); /* * Emit code. */ for (fragP = text_frag_root; fragP; fragP = fragP->fr_next) { register long count; register char *fill_literal; register long fill_size; know (fragP->fr_type == rs_fill); append (&next_object_file_charP, fragP->fr_literal, (unsigned long) fragP->fr_fix); fill_literal = fragP->fr_literal + fragP->fr_fix; fill_size = fragP->fr_var; know (fragP->fr_offset >= 0); for (count = fragP->fr_offset; count; count--) { append (&next_object_file_charP, fill_literal, (unsigned long) fill_size); } /* for each */ } /* for each code frag. */ know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers))); /* * Emit relocations. */ obj_emit_relocations (&next_object_file_charP, text_fix_root, (relax_addressT) 0); know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers))); #ifdef TC_I960 /* Make addresses in data relocation directives relative to beginning of * first data fragment, not end of last text fragment: alignment of the * start of the data segment may place a gap between the segments. */ obj_emit_relocations (&next_object_file_charP, data_fix_root, data0_frchainP->frch_root->fr_address); #else /* TC_I960 */ obj_emit_relocations (&next_object_file_charP, data_fix_root, text_last_frag->fr_address); #endif /* TC_I960 */ know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers))); /* * Emit line number entries. */ OBJ_EMIT_LINENO (&next_object_file_charP, lineno_rootP, the_object_file); know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers) + H_GET_LINENO_SIZE (&headers))); /* * Emit symbols. */ obj_emit_symbols (&next_object_file_charP, symbol_rootP); know ((next_object_file_charP - the_object_file) == (H_GET_HEADER_SIZE (&headers) + H_GET_TEXT_SIZE (&headers) + H_GET_DATA_SIZE (&headers) + H_GET_TEXT_RELOCATION_SIZE (&headers) + H_GET_DATA_RELOCATION_SIZE (&headers) + H_GET_LINENO_SIZE (&headers) + H_GET_SYMBOL_TABLE_SIZE (&headers))); /* * Emit strings. */ if (string_byte_count > 0) { obj_emit_strings (&next_object_file_charP); } /* only if we have a string table */ #ifdef BFD_HEADERS bfd_seek (stdoutput, 0, 0); bfd_write (the_object_file, 1, object_file_size, stdoutput); #else /* Write the data to the file */ output_file_append (the_object_file, object_file_size, out_file_name); #endif output_file_close (out_file_name); } /* non vms output */ #else /* VMS */ /* * Now do the VMS-dependent part of writing the object file */ VMS_write_object_file (H_GET_TEXT_SIZE (&headers), H_GET_DATA_SIZE (&headers), H_GET_BSS_SIZE (&headers), text_frag_root, data_frag_root); #endif /* VMS */ #else /* BFD_ASSEMBLER */ /* Set up symbol table, and write it out. */ if (symbol_rootP) { int i = 0, n; symbolS *symp; for (symp = symbol_rootP; symp; symp = symbol_next (symp)) { S_SET_VALUE (symp, S_GET_VALUE (symp) + symp->sy_frag->fr_address); /* So far, common symbols have been treated like undefined symbols. Put them in the common section now. */ if (S_IS_DEFINED (symp) == 0 && S_GET_VALUE (symp) != 0) S_SET_SEGMENT (symp, &bfd_com_section); #if 0 printf ("symbol `%s'\n\t@%x: value=%d type=%d forward=%x seg=%s\n", S_GET_NAME (symp), symp, S_GET_VALUE (symp), S_GET_DATA_TYPE (symp), symp->sy_forward, segment_name (symp->bsym->section)); #endif { int punt = 0; #ifdef obj_frob_symbol obj_frob_symbol (symp, punt); if (punt) goto punt_it; #endif #ifdef tc_frob_symbol tc_frob_symbol (symp, punt); if (punt) goto punt_it; #endif } /* If we don't want to keep this symbol, splice it out of the chain now. */ if (S_IS_LOCAL (symp)) { symbolS *prev, *next; punt_it: prev = symbol_previous (symp); next = symbol_next (symp); #ifdef DEBUG /* debugging: verify consistency */ { symbolS *p = symp, *n = symp; while (symbol_previous (p)) p = symbol_previous (p); while (symbol_next (n)) n = symbol_next (n); verify_symbol_chain (p, n); } #endif if (prev) { symbol_next (prev) = next; symp = prev; } else abort (); if (next) symbol_previous (next) = prev; else symbol_lastP = prev; #ifdef DEBUG /* debugging: verify consistency */ { symbolS *p = symp, *n = symp; while (symbol_previous (p)) p = symbol_previous (p); while (symbol_next (n)) n = symbol_next (n); verify_symbol_chain (p, n); } #endif continue; } i++; } n = i; if (n) { asymbol **asympp; boolean result; asympp = (asymbol **) bfd_alloc (stdoutput, n * sizeof (asymbol *)); symp = symbol_rootP; for (i = 0; i < n; i++, symp = symbol_next (symp)) { asympp[i] = symp->bsym; symp->written = 1; } result = bfd_set_symtab (stdoutput, asympp, n); assert (result == true); } } #ifdef obj_frob_file obj_frob_file (); #endif /* Now that all the sizes are known, and contents correct, we can start writing the file. */ bfd_map_over_sections (stdoutput, write_contents, (char *) 0); output_file_close (out_file_name); #endif /* BFD_ASSEMBLER */ } #endif /* BFD */ /* * relax_segment() * * Now we have a segment, not a crowd of sub-segments, we can make fr_address * values. * * Relax the frags. * * After this, all frags in this segment have addresses that are correct * within the segment. Since segments live in different file addresses, * these frag addresses may not be the same as final object-file addresses. */ static int is_dnrange (f1, f2) struct frag *f1; struct frag *f2; { for (; f1; f1 = f1->fr_next) if (f1->fr_next == f2) return 1; return 0; } /* Relax_align. Advance location counter to next address that has 'alignment' lowest order bits all 0s. */ /* How many addresses does the .align take? */ static relax_addressT relax_align (address, alignment) register relax_addressT address; /* Address now. */ register long alignment; /* Alignment (binary). */ { relax_addressT mask; relax_addressT new_address; mask = ~((~0) << alignment); new_address = (address + mask) & (~mask); if (linkrelax) /* We must provide lots of padding, so the linker can discard it when needed. The linker will not add extra space, ever. */ new_address += (1 << alignment); return (new_address - address); } void relax_segment (segment_frag_root, segment) struct frag *segment_frag_root; segT segment; { register struct frag *fragP; register relax_addressT address; #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER) know (segment == SEG_DATA || segment == SEG_TEXT || segment == SEG_BSS); #endif /* In case md_estimate_size_before_relax() wants to make fixSs. */ subseg_change (segment, 0); /* For each frag in segment: count and store (a 1st guess of) fr_address. */ address = 0; for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) { fragP->fr_address = address; address += fragP->fr_fix; switch (fragP->fr_type) { case rs_fill: address += fragP->fr_offset * fragP->fr_var; break; case rs_align: address += relax_align (address, fragP->fr_offset); break; case rs_org: /* Assume .org is nugatory. It will grow with 1st relax. */ break; case rs_machine_dependent: address += md_estimate_size_before_relax (fragP, segment); break; #ifndef WORKING_DOT_WORD /* Broken words don't concern us yet */ case rs_broken_word: break; #endif default: BAD_CASE (fragP->fr_type); break; } /* switch(fr_type) */ } /* for each frag in the segment */ /* Do relax(). */ { long stretch; /* May be any size, 0 or negative. */ /* Cumulative number of addresses we have */ /* relaxed this pass. */ /* We may have relaxed more than one address. */ long stretched; /* Have we stretched on this pass? */ /* This is 'cuz stretch may be zero, when, in fact some piece of code grew, and another shrank. If a branch instruction doesn't fit anymore, we could be scrod. */ do { stretch = stretched = 0; for (fragP = segment_frag_root; fragP; fragP = fragP->fr_next) { long growth = 0; unsigned long was_address; long offset; symbolS *symbolP; long target; long after; long aim; was_address = fragP->fr_address; address = fragP->fr_address += stretch; symbolP = fragP->fr_symbol; offset = fragP->fr_offset; switch (fragP->fr_type) { case rs_fill: /* .fill never relaxes. */ growth = 0; break; #ifndef WORKING_DOT_WORD /* JF: This is RMS's idea. I do *NOT* want to be blamed for it I do not want to write it. I do not want to have anything to do with it. This is not the proper way to implement this misfeature. */ case rs_broken_word: { struct broken_word *lie; struct broken_word *untruth; /* Yes this is ugly (storing the broken_word pointer in the symbol slot). Still, this whole chunk of code is ugly, and I don't feel like doing anything about it. Think of it as stubbornness in action. */ growth = 0; for (lie = (struct broken_word *) (fragP->fr_symbol); lie && lie->dispfrag == fragP; lie = lie->next_broken_word) { if (lie->added) continue; offset = (lie->add->sy_frag->fr_address + S_GET_VALUE (lie->add) + lie->addnum - (lie->sub->sy_frag->fr_address + S_GET_VALUE (lie->sub))); if (offset <= -32768 || offset >= 32767) { if (flagseen['K']) as_warn (".word %s-%s+%ld didn't fit", S_GET_NAME (lie->add), S_GET_NAME (lie->sub), lie->addnum); lie->added = 1; if (fragP->fr_subtype == 0) { fragP->fr_subtype++; growth += md_short_jump_size; } for (untruth = lie->next_broken_word; untruth && untruth->dispfrag == lie->dispfrag; untruth = untruth->next_broken_word) if ((untruth->add->sy_frag == lie->add->sy_frag) && S_GET_VALUE (untruth->add) == S_GET_VALUE (lie->add)) { untruth->added = 2; untruth->use_jump = lie; } growth += md_long_jump_size; } } break; } /* case rs_broken_word */ #endif case rs_align: growth = (relax_align ((relax_addressT) (address + fragP->fr_fix), offset) - relax_align ((relax_addressT) (was_address + fragP->fr_fix), offset)); break; case rs_org: target = offset; if (symbolP) { #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER) know ((S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE) || (S_GET_SEGMENT (symbolP) == SEG_DATA) || (S_GET_SEGMENT (symbolP) == SEG_TEXT) || S_GET_SEGMENT (symbolP) == SEG_BSS); know (symbolP->sy_frag); know (!(S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE) || (symbolP->sy_frag == &zero_address_frag)); #endif target += S_GET_VALUE (symbolP) + symbolP->sy_frag->fr_address; } /* if we have a symbol */ know (fragP->fr_next); after = fragP->fr_next->fr_address; growth = ((target - after) > 0) ? (target - after) : 0; /* Growth may be negative, but variable part of frag cannot have fewer than 0 chars. That is, we can't .org backwards. */ growth -= stretch; /* This is an absolute growth factor */ break; case rs_machine_dependent: { const relax_typeS *this_type; const relax_typeS *start_type; relax_substateT next_state; relax_substateT this_state; this_state = fragP->fr_subtype; start_type = this_type = md_relax_table + this_state; target = offset; if (symbolP) { #if !defined (MANY_SEGMENTS) && !defined (BFD_ASSEMBLER) know ((S_GET_SEGMENT (symbolP) == SEG_ABSOLUTE) || (S_GET_SEGMENT (symbolP) == SEG_DATA) || (S_GET_SEGMENT (symbolP) == SEG_BSS) || (S_GET_SEGMENT (symbolP) == SEG_TEXT)); #endif know (symbolP->sy_frag); know (!(S_GET_SEGMENT (symbolP) == absolute_section) || symbolP->sy_frag == &zero_address_frag); target += S_GET_VALUE (symbolP) + symbolP->sy_frag->fr_address; /* If frag has yet to be reached on this pass, assume it will move by STRETCH just as we did. If this is not so, it will be because some frag between grows, and that will force another pass. */ /* JF was just address */ /* JF also added is_dnrange hack */ /* There's gotta be a better/faster/etc way to do this. . . */ /* gnu@cygnus.com: I changed this from > to >= because I ran into a zero-length frag (fr_fix=0) which was created when the obstack needed a new chunk JUST AFTER the opcode of a branch. Since fr_fix is zero, fr_address of this frag is the same as fr_address of the next frag. This zero-length frag was variable and jumped to .+2 (in the next frag), but since the > comparison below failed (the two were =, not >), "stretch" was not added to the target. Stretch was 178, so the offset appeared to be .-176 instead, which did not fit into a byte branch, so the assembler relaxed the branch to a word. This didn't compare with what happened when the same source file was assembled on other machines, which is how I found it. You might want to think about what other places have trouble with zero length frags... */ if (symbolP->sy_frag->fr_address >= was_address && is_dnrange (fragP, symbolP->sy_frag)) { target += stretch; } } /* if there's a symbol attached */ aim = target - address - fragP->fr_fix; /* The displacement is affected by the instruction size for the 32k architecture. I think we ought to be able to add fragP->fr_pcrel_adjust in all cases (it should be zero if not used), but just in case it breaks something else we'll put this inside #ifdef NS32K ... #endif */ #ifdef TC_NS32K aim += fragP->fr_pcrel_adjust; #endif /* TC_NS32K */ if (aim < 0) { /* Look backwards. */ for (next_state = this_type->rlx_more; next_state;) if (aim >= this_type->rlx_backward) next_state = 0; else { /* Grow to next state. */ this_state = next_state; this_type = md_relax_table + this_state; next_state = this_type->rlx_more; } } else { #ifdef M68K_AIM_KLUDGE M68K_AIM_KLUDGE (aim, this_state, this_type); #endif /* Look forwards. */ for (next_state = this_type->rlx_more; next_state;) if (aim <= this_type->rlx_forward) next_state = 0; else { /* Grow to next state. */ this_state = next_state; this_type = md_relax_table + this_state; next_state = this_type->rlx_more; } } growth = this_type->rlx_length - start_type->rlx_length; if (growth != 0) fragP->fr_subtype = this_state; } break; default: BAD_CASE (fragP->fr_type); break; } if (growth) { stretch += growth; stretched++; } } /* For each frag in the segment. */ } while (stretched); /* Until nothing further to relax. */ } /* do_relax */ /* * We now have valid fr_address'es for each frag. */ /* * All fr_address's are correct, relative to their own segment. * We have made all the fixS we will ever make. */ } /* relax_segment() */ /* fixup_segment() Go through all the fixS's in a segment and see which ones can be handled now. (These consist of fixS where we have since discovered the value of a symbol, or the address of the frag involved.) For each one, call md_apply_fix to put the fix into the frag data. Result is a count of how many relocation structs will be needed to handle the remaining fixS's that we couldn't completely handle here. These will be output later by emit_relocations(). */ static long fixup_segment (fixP, this_segment_type) register fixS *fixP; segT this_segment_type; /* N_TYPE bits for segment. */ { register long seg_reloc_count; register symbolS *add_symbolP; register symbolS *sub_symbolP; long add_number; register int size; register char *place; register long where; register char pcrel; register fragS *fragP; register segT add_symbol_segment = absolute_section; seg_reloc_count = 0; /* If the linker is doing the relaxing, we must not do any fixups */ if (linkrelax) for (; fixP; fixP = fixP->fx_next) seg_reloc_count++; else for (; fixP; fixP = fixP->fx_next) { fragP = fixP->fx_frag; know (fragP); where = fixP->fx_where; place = fragP->fr_literal + where; size = fixP->fx_size; add_symbolP = fixP->fx_addsy; #ifdef TC_I960 if (fixP->fx_callj && TC_S_IS_CALLNAME (add_symbolP)) { /* Relocation should be done via the associated 'bal' entry point symbol. */ if (!TC_S_IS_BALNAME (tc_get_bal_of_call (add_symbolP))) { as_bad ("No 'bal' entry point for leafproc %s", S_GET_NAME (add_symbolP)); continue; } fixP->fx_addsy = add_symbolP = tc_get_bal_of_call (add_symbolP); } #endif sub_symbolP = fixP->fx_subsy; add_number = fixP->fx_offset; pcrel = fixP->fx_pcrel; if (add_symbolP) add_symbol_segment = S_GET_SEGMENT (add_symbolP); if (sub_symbolP) { if (!add_symbolP) { /* Its just -sym */ if (S_GET_SEGMENT (sub_symbolP) != absolute_section) as_bad ("Negative of non-absolute symbol %s", S_GET_NAME (sub_symbolP)); add_number -= S_GET_VALUE (sub_symbolP); } else if ((S_GET_SEGMENT (sub_symbolP) == add_symbol_segment) && (SEG_NORMAL (add_symbol_segment) || (add_symbol_segment == absolute_section))) { /* Difference of 2 symbols from same segment. Can't make difference of 2 undefineds: 'value' means something different for N_UNDF. */ #ifdef TC_I960 /* Makes no sense to use the difference of 2 arbitrary symbols as the target of a call instruction. */ if (fixP->fx_callj) { as_bad ("callj to difference of 2 symbols"); } #endif /* TC_I960 */ add_number += S_GET_VALUE (add_symbolP) - S_GET_VALUE (sub_symbolP); add_symbolP = NULL; fixP->fx_addsy = NULL; } else { /* Different segments in subtraction. */ know (!(S_IS_EXTERNAL (sub_symbolP) && (S_GET_SEGMENT (sub_symbolP) == absolute_section))); if ((S_GET_SEGMENT (sub_symbolP) == absolute_section)) { add_number -= S_GET_VALUE (sub_symbolP); } else { as_bad ("Can't emit reloc {- %s-seg symbol \"%s\"} @ file address %d.", segment_name (S_GET_SEGMENT (sub_symbolP)), S_GET_NAME (sub_symbolP), fragP->fr_address + where); } /* if absolute */ } } /* if sub_symbolP */ if (add_symbolP) { if (add_symbol_segment == this_segment_type && pcrel) { /* * This fixup was made when the symbol's segment was * SEG_UNKNOWN, but it is now in the local segment. * So we know how to do the address without relocation. */ #ifdef TC_I960 /* reloc_callj() may replace a 'call' with a 'calls' or a 'bal', in which cases it modifies *fixP as appropriate. In the case of a 'calls', no further work is required, and *fixP has been set up to make the rest of the code below a no-op. */ reloc_callj (fixP); #endif /* TC_I960 */ add_number += S_GET_VALUE (add_symbolP); add_number -= md_pcrel_from (fixP); pcrel = 0; /* Lie. Don't want further pcrel processing. */ fixP->fx_addsy = NULL; /* No relocations please. */ } else { if (add_symbol_segment == absolute_section) { #ifdef TC_I960 /* See comment about reloc_callj() above. */ reloc_callj (fixP); #endif /* TC_I960 */ add_number += S_GET_VALUE (add_symbolP); fixP->fx_addsy = NULL; add_symbolP = NULL; } else if (add_symbol_segment == undefined_section #ifdef BFD_ASSEMBLER || add_symbol_segment == &bfd_com_section #endif ) { #ifdef TC_I960 if ((int) fixP->fx_bit_fixP == 13) { /* This is a COBR instruction. They have only a * 13-bit displacement and are only to be used * for local branches: flag as error, don't generate * relocation. */ as_bad ("can't use COBR format with external label"); fixP->fx_addsy = NULL; /* No relocations please. */ continue; } /* COBR */ #endif /* TC_I960 */ #ifdef OBJ_COFF #ifdef TE_I386AIX if (S_IS_COMMON (add_symbolP)) add_number += S_GET_VALUE (add_symbolP); #endif /* TE_I386AIX */ #endif /* OBJ_COFF */ ++seg_reloc_count; } else { seg_reloc_count++; add_number += S_GET_VALUE (add_symbolP); } } /* if not in local seg */ } /* if there was a + symbol */ if (pcrel) { add_number -= md_pcrel_from (fixP); if (add_symbolP == 0) { fixP->fx_addsy = &abs_symbol; ++seg_reloc_count; } /* if there's an add_symbol */ } /* if pcrel */ if (!fixP->fx_bit_fixP) { if ((size == 1 && (add_number & ~0xFF) && ((add_number & ~0xFF) != (-1 & ~0xFF))) || (size == 2 && (add_number & ~0xFFFF) && ((add_number & ~0xFFFF) != (-1 & ~0xFFFF)))) { as_bad ("Value of %d too large for field of %d bytes at 0x%x", add_number, size, fragP->fr_address + where); } /* generic error checking */ #ifdef WARN_SIGNED_OVERFLOW_WORD /* Warn if a .word value is too large when treated as a signed number. We already know it is not too negative. This is to catch over-large switches generated by gcc on the 68k. */ if (!flagseen['J'] && size == 2 && add_number > 0x7fff) as_bad ("Signed .word overflow; switch may be too large; %d at 0x%x", add_number, fragP->fr_address + where); #endif } /* not a bit fix */ #ifdef BFD_ASSEMBLER md_apply_fix (fixP, &add_number); #else md_apply_fix (fixP, add_number); #endif } /* For each fixS in this segment. */ #ifdef OBJ_COFF #ifdef TC_I960 { fixS *topP = fixP; /* two relocs per callj under coff. */ for (fixP = topP; fixP; fixP = fixP->fx_next) { if (fixP->fx_callj && fixP->fx_addsy != 0) { ++seg_reloc_count; } /* if callj and not already fixed. */ } /* for each fix */ } #endif /* TC_I960 */ #endif /* OBJ_COFF */ return (seg_reloc_count); } /* fixup_segment() */ /* end of write.c */